"Much to the disappointment of my staff when they told me the two games in London were sold out, I said, 'Okay, what's next and what can we do to continue our progress, in the UK in particular and internationally in general?'" Goodell said.

The NFL has played an annual game in London since 2007 and held two games in 2012. The popularity of the games in London is not lost on the NFL and adding a third game as early as 2014 is a possibility.

Interest in the NFL in international markets has never been in question, but travel and scheduling constraints have always limited the league's ability to establish a consistent presence outside the U.S.

The Buffalo Bills have long sought to capitalize on the nearby Toronto market but have had limited opportunity to play games in the neighboring Canadian city -- the Bills hosted the Seattle Seahawks for a regular season game in 2012.

There are two NFL games scheduled for London in 2013: Pittsburgh Steelers vs. Minnesota Vikings on Sept. 29 and the San Francisco 49ers vs. Jacksonville Jaguars on Oct. 27.